Chronic Pontine Stroke:Diffusion Tensor Imaging Of Corticospinal Tract Indicating Prognosis Of Motor Outcome

Objective:To investigate the relationship between diffusion indexes of corticospinal tract(CST)and neurological motor function outcome in chronic pontine stroke patients.Method:Diffusion tensor imaging(DTI)sequence was performed in 27 patients with chronic pontine stroke and 27 normal controls.Fractional anisotropic(FA)values along the area of the CST,the track number and length of the CST were measured.Fractional anisotropic ratios in the CST of stroke subjets were compared with those in control subjects by using the Student t test,and their relationships with clinical scores were analyzed by using Spearman correlation analysis.Result:1.Fractional anisotropic values were decreased in the infarct area,cerebral peduncle,posterior limb of internal capsule and precentral gyrus compared with those in the contralateral side.The number of the CST is also decreased in ipsilateral side of the infarct(P<0.01).Fractional anisotropic ratios in the CST above the pontine and CST rnum decreased significantly compared with those in control subjects(P<0.01).2.Fractional anisotropic ratios in cerebral peduncle,posterior limb of internal capsule and CST rnum correlated positively with Fugl-Meyer scores(r=0.824?0.672?0.651,P<0.001),and correlated negatively with modified Rankin scale scores(r=-0.835?-0.604?-0.645,P?0.001).3.The injury degree of the CST correlated negatively with Fugl-Meyer scores(r=-0.627,P<0.001).Conclusion:Fractional anisotropic ratios in cerebral peduncle,posterior limb of internal capsule and CST rnum are associated with motor outcome,suggesting that diffusion tensor imaging may be applicable for outcome evaluation.